A probabilistic finger biodynamic model better depicts the roles of the flexors during unloaded flexion

Assessing Finger Joint Biomechanics by Applying Equal Force to Flexor Tendons In Vitro Using a Novel Simultaneous Approach

“…In addition, our finding that the FDS was more involved than the FDP early in flexion was consistent with those of other studies, such as the 2010 study by Li and Zhang, in which a computer model was used to predict the tendons’ contributions during flexion [ 12 , 19 , 42 ]. The results from our study and that of Li and Zhang were also consistent with those of the 1994 study by Greenwald et el., which showed that the FDP is not the primary flexor because, to initiate DIP movement, it has to overcome the EDC’s counterforce and rely on the pulley system to move a long distance efficiently [ 3 , 12 , 43 , 44 ]. (3) After initial movement, the DIP continued more or less synchronously with the PIP joint, and these joints’ motions increased more quickly compared to the MCP’s steady increase.…”

“…Thus, the FDS and FDP excursions were highly correlated during individual joint motions and free joint movement. Additionally, our results show that, despite the FDP’s dominance during the whole movement, the FDS played an increasingly greater supporting role as greater force was required [ 8 , 12 , 17 , 39 , 45 ]. Moreover, our study provides specific information for future research about the relationship between the FDS and FDP at different instants during flexion.…”

“…Some of these studies assumed the FDS is completely inactive or triggered just slightly early in flexion. Therefore, they gathered evidence only from the FDP [ 12 – 15 ]. Later studies, however, analyzed both the FDS and FDP and found that both tendons are active, although these studies did not explore the specific relationship between the tendons.…”

“…These studies further defined these tendons’ coordination with a “simultaneous approach,” testing them together in vivo [ 16 – 18 ]. However, previous studies were all performed in vivo and therefore were limited to examining tendon gliding postures, which cannot clarify the specific kinetics or kinematics of the tendons’ simultaneous function [ 5 , 12 , 16 – 21 ]. Our main purpose was to use a novel simultaneous approach to explore the two tendons’ contributions by determining finger joint angle and tendon excursion changes in response to equal applied force in various finger motion tasks in a normal pulley system.…”

Probabilistic sensitivity analysis of in-vehicle reach tasks for digital human models considering anthropometric measurement uncertainty

“…Spine q 1 Spine 1 tilt q 2 Spine 1 bend q 3 Spine 1 rotation q 4 Spine 2 tilt q 5 Spine 2 bend q 6 Spine 2 rotate q 7 Spine 3 tilt q 8 Spine 3 bend q 9 Spine 3 rotation q 10 Spine 4 tilt q 11 Spine 4 bend q 12 Spine 4 rotation Upper Right/Left q 13 /q 22 Clavicle tilt q 14 /q 23 Clavicle rotation q 15 /q 24 Shoulder up and down q 16 /q 25 Shoulder forward and back q 17 /q 26 Shoulder twist q 18 /q 27 Elbow bend q 19 /q 28 Elbow twist q 20 /q 29 Wrist tilt q 21 /q 30 Wrist bend Neck/Head q 31 Neck tilt q 32 Neck bend q 33 Neck rotation q 34 Head tilt q 35 Head bend Lower Right/Left q 36 /q 43 Hip tilt q 37 /q 44 Hip bend q 38 /q 45 Hip rotation q 39 /q 46 Knee bend q 40 /q 47 Ankle bend q 41 /q 48 Ankle tilt q 42 /q 49 Foot bend…”